Blowpipe



G. L. WALKER.

BLowPlPE. APPLICATION FILED NOV. 20, 1920.

Patented Aug. 9, 1921.

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GEORGE L. WALKER, OF NEW YORK, N.' Y.,

ASSIGNOR TO AIR REDUCTION COMPANY,

INC., A. CORPORATION OF NEW YORK.

- BLowPIrr. v

Specification of Letters Patent.

Y Patented Aug. 9, 1921.

Original application led Hay 1, 1919, Serial No. 294,004. Divided andthis application led November To all 'whom it may concern:

Be it known that I, GEORGE L. WALKER, a citizen ofthe United States,residing at New York, in the county of New York, State of New York, haveinvented certain new and useful Improvements in Blowpipes; and I dohereby declare the-following to be a full,

clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

e This invention relates to blow pipes burning mixtures of combustibleand oxidizingciples. herein described may be employed in blowpipesdiffering in details of construction from those mentioned. The inventionis in fact general application to blowpipes having grooves in one of twocoperatmg surfaces, whereby one of the gases is conveyed to and mixedwith the other to provide a combustible mixture which is discharged andburned to produce high temperature flames. V

The object of the invention is to improve the operation-of blowpipes byinsuring the proper mixture of the gaseous constituents and particularlyto prevent flash-back or backward propagation of the flame in thedischarge passage of the blowpipe tip.

Further ob'ects and advantages of the invention will e apparent as it isbetter understood, by reference to the following specification andaccompanying drawing illustrating a preferred embodiment of theinvention, in which:

Figure 1 is a longitudinal section through a blowpipe head and a portionof a tip;

2 is a section in the line 2 2 of Fig. 1; an

Fig. 3 is a rear end elevationof the tip illustrated in Fig.' 1.

` It has been discovered as explained in thel Letters Patent to GeorgeL. -Walker, No. 1310099 that the best results are obtained in theoperation of blowpipeshwhen the pressure .of the two gases are su or thepressure .of the acetylene slightly exstantially equal '20, 1920. serialNn. 425,334.

ceeds that of the oxygen. In the operation of blowpipes as usuallyconstructed, any obstruction of the discharge passage results in anenrichment of the mixture in oxygen and corresponding increase in therate of flame propagation therein. Usually a flash-back results fromthis abnormal condition. In the operation of blowpipes as hereincontemplated, this objectionable result is avoided. The pressures of theentering gases being substantially equal, any obstruction in the.

discharge passage results in a decreased flow 'of both gases, while themixture remains normal, or, 1f the pressure of the acetylene exceedsslightly that ofthe oxygen, the mixture is enriched in acetylene withcorresponding decrease in the rate of flame propagation in the mixture.

I have discovered that the operation of blowpipes in the mannerdescribed is materially improved when the combustible gas is conveyedthrough` passages of uniformly diminishing cross-sectional area and ismixed with the oxidizing gas immediately upon delivery from suchpassages. By conveying the .combustible gas in this manner, themaintenance of the desired velocity is assured, no opportunity beingafforded for the gas to expand until it flows into the discharge passageof the tip. As 'a result of the operation as described, I find that thecharacter of the mixture is improved, and that regulation of the flameand the prevention or rearward propagation thereof are readilyaccomplished. The operation of the blowpipe, particularly by relativelyunskilled operators is made comparatively simple.

' Referring to the drawing in which the head and a portion of the tipare illustrated on an enlarged scale, to more clearly distinguish theinvention, 5 indicates the head having passages 6 and 7 for oxidizingand combustible gases which are delivered thereto through pipes 8 and 9from a suitable source. The passage 6 terminates at the apex of aconical seat 10 in which an annular groove 11 is formed. Duets 12connect the channel with the passage 7.

A tip 13 having a discharge passage 14 is held in assembled relationwith the head 5 by a nut 14. The tip 13 is provided' at its inner endwith a conical recess, the surface of which conforms to the seat andforms therewitha gas tight joint surrounding the channel 11, andeifectually preventing escape of gases from the head. One or more roovesare milled, pressed or otherwise ormed in the recessed surface and serveto convey the combustible gas from the channel 11 to themouth of thedischarge passage 14, Where it mixes with the oxidizing gas from thepassage 6.

- bustible gas issues therefore from'these passages and is delivered tothe oxidizing gas,

at maximum velocity with resulting 1mprovement of the mixture and otheradvanta es.

t .is to be understood that in the accompanying drawmg I haveillustrated a pre-v ferred mode of applying the invention, and

that changes may bemade therein by varying both the width and depth ofthe grooves to provide passage of uniformly diminishing cross-sectional-area for the gas. The depth and Width of the grooves may be vvariedandare in fact carefully propor- `tioned to provide proper mixtures intlps 1nuniformly diminishingcross sectional area' of the passages.

I claim In a blovvpipe, the combination With a head having oxidizing andcombustible gas passages, of a tip adapted to be assembled therewith andprovided With a discharge passage, said head having a projecting conicalseat and said tip having a corresponding recessed surface provided withagroove of substantially uniform depth and diminishing Width to provideapassage of diminishing cross sectional area arranged to delivercombustible gas to said discharge passage.

In testimony whereof I aiix my signature.

lGEORGE L. WALKER.

